It has recently been discovered that extremely small particles of plastic exhibit unexpectedly superior processing properties for the production of new plastic articles. U.S. Pat. Nos. 6,734,234 and 5,899,392, for example, disclose that extremely small particles of RPET produced by comminuting RPET flakes may easily be decontaminated and recycled to make plastic containers.
However, extremely small particles of plastic are difficult to transport and otherwise handle. Generally, the handling of fine powders requires specialized equipment such as customized vacuum conveying systems, dense phase conveyors, crystallizers, dryers, bins, tanks, and augers. Such handling equipment is expensive, and costly to operate and maintain. For these reasons, manufacturers prefer to use larger plastic flakes or pellets and conventional handling equipment in the manufacture of plastic articles, but thereby lose the benefits that could otherwise be realized by the use of extremely small particles of plastic.
It would be desirable to treat extremely small particles of plastic, to prepare a stock material that is easy to handle in conventional processing equipment, yet which substantially retains the processing advantages, operability, and utility exhibited by extremely small particles of plastic.